JavaScript基础------（数组）

var arr2 = new Array();
arr2["湖南"] = ["长沙","湘潭","株洲"];    
arr2["广东"] = ["广州","深圳","珠海"];
            
document.write(arr2.length + "<br>");  //arr2.length = 0
document.write(arr2["湖南"].length + "<br>");
            
for(var i in arr2){
    document.write("<h4>" + i + "</h4>");
    for(var j in arr2[i]){
    document.write(arr2[i][j] + "&nbsp;&nbsp;&nbsp;");
    }
}